Pizza is a food that originated in Italy and is very popular all over the world. The usual practice of pizza is to cover tomato sauce, cheese and other ingredients with fermented round dough cakes and bake them in an oven. Cheese are usually mozzarella cheese, but there are also mixed forms of several cheeses, including Parmesan cheese, romano, Italian country cheese (ricotta) or Monterey Jack cheese (Monterey Jack) etc. The pizza shop is called Pizzeria. According to statistics, there are about 20000 pizza shops in Italy. The world's largest pizza chain is Pizza Hut in the United States